Under what circumstances can an ABN be reactivated?

An Australian Business Number (ABN) will be reactivated when an entity becomes registered for a second or subsequent time. The earlier registration was correctly cancelled with the second or subsequent registration following a period when the entity was not entitled to an ABN. The Registrar, in registering the entity, allocates the ABN previously used.

This may occur when a client sells their business and cancels their ABN. Twelve months later, as the same entity, they purchase a new business.

An ABN cannot be reactivated if there has been a change in business structure. For example, a change from a sole trader to a partnership. In this situation a new ABN registration is required because there is a change in entity.